Interleukin-9 Deletion Relieves Vascular Dysfunction and Decreases Blood Pressure via the STAT3 Pathway in Angiotensin II-Treated Mice

Background. Multiple interleukin (IL) family members were reported to be closely related to hypertension. We aimed to investigate whether IL-9 affects angiotensin II- (Ang II-) induced hypertension in mice. Methods. Mice were treated with Ang II, and IL-9 expression was determined. In addition, effects of IL-9 knockout (KO) on blood pressure were observed in Ang II-infused mice. To determine whether the effects of IL-9 on blood pressure was mediated by the signal transducer and activator of the transcription 3 (STAT3) pathway, Ang II-treated mice were given S31-201. Furthermore, circulating IL-9 levels in patients with hypertension were measured. Results. Ang II treatment increased serum and aortic IL-9 expression in a dose-dependent manner; IL-9 levels were the highest in the second week and continued to remain high into the fourth week after the treatment. IL-9 KO downregulated proinflammatory cytokine expression, whereas it upregulated anti-inflammatory cytokine levels, relieved vascular dysfunction, and decreased blood pressure in Ang II-infused mice. IL-9 also reduced smooth muscle 22α (SM22α) expression and increased osteopontin (OPN) levels both in mice and in vitro. The effects of IL-9 KO on blood pressure and inflammatory response were significantly reduced by S31-201 treatment. Circulating IL-9 levels were significantly increased in patients with the hypertension group than in the control group, and elevated IL-9 levels positively correlated with both systolic blood pressure and diastolic blood pressure in patients with hypertension. Conclusions. IL-9 KO alleviates inflammatory response, prevents phenotypic transformation of smooth muscle, reduces vascular dysfunction, and lowers blood pressure via the STAT3 pathway in Ang II-infused mice. IL-9 might be a novel target for the treatment and prevention of clinical hypertension

Adipocyte thyroid hormone β receptor-mediated hormone action fine-tunes the intracellular glucose and lipid metabolism and systemic homeostasis

Thyroid hormone (TH) has a profound effect on energy metabolism and systemic homeostasis. Adipose tissues are crucial for maintaining whole-body homeostasis, however, whether TH regulates systemic metabolic homeostasis through its action on the adipose tissues is unclear. Here, we demonstrate that systemic administration of triiodothyronine (T3), the active form of TH, affects both inguinal white adipose tissue (iWAT) and whole-body metabolism. Taking advantage of the mouse model lacking adipocyte TH receptor α (TRα) or β (TRβ) we show that TRβ is the major TR isoform that mediates the T3 action on the expression of genes involved in multiple metabolic pathways in iWAT, including glucose uptake and usage, de novo fatty acid synthesis, and both UCP1-dependent and -independent thermogenesis. Moreover, our results indicate that ChREBP in iWAT is regulated by T3, thereby being critically involved in T3-regulated glucose and lipid metabolism and energy dissipation. Meanwhile, mice with adipocyte TRβ deficiency are susceptible to diet-induced obesity and metabolic dysregulation, suggesting that TRβ in adipocytes may sever as a potential target for metabolic diseases. </p